Early Prediction of Spontaneous Patent Ductus Arteriosus (PDA) Closure and PDA-Associated Outcomes

Overview

Patent ductus arteriosus (PDA), very common in preterm infants, is the delayed closure of a fetal blood vessel that limits blood flow through the lungs. PDA is associated with mortality and harmful long term outcomes including chronic lung disease and neurodevelopmental delay. Although, treatments to close PDA likely benefit some infants, widespread routine treatment of all preterm infants with PDA may not improve important outcomes. Left untreated, most PDAs close spontaneously. Thus, PDA treatment is increasingly controversial and varies markedly between hospitals and individual providers. The relevant and still unanswered clinical question is not whether to treat all preterm infants with PDA, but whom to treat and when. Treatment detriments may outweigh benefits, since all forms of deliberate PDA closure have potential adverse effects, especially in infants destined for early, spontaneous PDA closure. Unfortunately, clinicians cannot currently predict in the 1st month which infants are at highest risk for persistent PDA, and which combination of clinical risk factors, echocardiographic (echo) measurements, and serum biomarkers may best predict PDA-associated harm. The American Academy of Pediatrics has acknowledged early identification of infants at high-risk from PDA as a key research goal for informing future PDA-treatment effectiveness trials. Our objective is to use a prospective cohort of untreated infants with PDA to predict spontaneous ductal closure timing and identify echo measurements and biomarkers that are present in the 1st postnatal month and associated with long-term impairment. Our central hypothesis is that these risk factors can be determined to inform appropriate clinical treatments when necessary. Clinical, serum and urine biomarkers (BNP, NTpBNP, NGAL, H-FABP), and echo variables sequentially collected during each of the first 4 postnatal weeks will be examined. In addition myocardial deformation imaging (MDI) and tissue Doppler imaging (TDI), innovative echo methods, will facilitate the quantitative evaluation of myocardial performance. Aim 1 will estimate the probability of spontaneous PDA closure and predict the timing of ductal closure using echo, biomarker, and clinical predictors. Aim 2 will specify which echo predictors and biomarkers are associated with mortality and severity of respiratory illness at 36-weeks PMA. Aim 3 will identify which echo predictors and biomarkers are associated with 22- to 26-month neurodevelopment. All models will be validated in a separate cohort. This project will significantly contribute to clinical outcomes and PDA management by reducing unnecessary and harmful overtreatment of infants with a high probability of early spontaneous PDA closure, and will permit the development of outcomes-focused trials to examine the effectiveness of PDA closure in those "high-risk" infants most likely to receive benefit.